Heater plug for support during starting of diesel engine, has tubular metal casing with axial opening, and part of wall surface of axial opening, with which O-ring is in close contact and part of outer peripheral surface of centre shaft

摘要

The plug has a tubular metal casing (40) with an axial opening (43). A part of the wall surface of the axial opening, with which the O-ring (70) is in close contact and/or a part of the outer peripheral surface of the centre shaft (30), with which the O-ring is in close contact, is formed as a slant surface (47). The slant surface increases the free space between the wall surface of the axial opening and the centre shaft, towards the axis (O) to the rear end side. The O-ring extends around the axis is configured such that a distance between two lines.